I bought a Marlin 5 Gen 3 MTB and the shop removed the front wheel to get it into my car. I was instructed when refitting the wheel to tighten the axle back up with an allen key.
When I did this at home, the nut easily stripped. The shop gave me a replacement nut but it’s from
a quick-release skewer and is too tall for my non quick release axle to reach through the nut’s metal core and into the plastic section that performs a locking function to stop it rattling loose.
At this point i realised that the quick-release nut (pictured right) has a steel threaded core whereas the Gen 3 nut (pictured left) is alloy including the thread – save for a nyloc-style insert at the outer end. There is only 4mm of M5 alloy thread in this nut and in my experience it’s quite weak and easily stripped.
I recored the alloy nut with a steel M5 helicoil/thread insert and it’s clearly much stronger now. The original design seems somewhat defective – hopefully Trek might pick up on that and supersede the alloy nut with something more durable.
by propulsionman